The Applicant's U.S. patent application Ser. No. 09/010,387 describes how descriptive meta-data can be used to transfer of information across an interface between a network element (“NE”) and a network management system (“NMS”) and also describes how associated connection rule and constraint data can be transferred.
ITU-T standard G.805 addresses the generic functional architecture of transport networks and can be located on the world wide web via the www.itu.org website, as is known to those skilled in the art. G.805 describes how the transfer of telecommunications information from one point to other point(s) in a transport network may be modelled.
As is known to those skilled in the art, complex transport networks are often large with various components and an appropriate network model having well-defined functional entities is necessary for its design and management. In G.805 the transport network is described using a generic functionality which is independent of the implementation technology.
Using a model based upon a generic, functional description, the transport network can be described in an abstract manner using a set of abstract architectural components which are defined by the function they perform using processing information terms or by the relationships they describe between other architectural components. For example, an architectural component can be defined by a function which acts on information presented at input and which presents processed information at output. Thus the architectural component is a functional resource which can be defined and characterised by the information process between its input and output. Associating architectural components together enables network elements to be represented from which a “real” network may be constructed.
Within a transport network there exist repeated assembly patterns of internally static and/or deterministically constrained functional resources. In U.S. Ser. No. 09/010,387, templates are constructed to represent these patterns of functional resource structures.
The patterns are given a stability by basing them on an “endpoint” or stable anchor point in an NE. An example of an “endpoint” would thus be a physical port in the NE. A NMS needs only to know the name of the endpoint and an identifier for the pattern to be built from it to determine the functional resources associated with that endpoint. U.S. Ser. No. 09/010,387 describes how each endpoint has a pointer to a template which describes the set of functional resources (including the connection rules and constraints) related to that endpoint.
The term template is used here in its conventional form, i.e., it provides a model form for the meta-data describing a particular set of functional resources such that the meta-data can be utilised as a resource by various algorithmic applications.
In ITU Recommendation G.805 network resources, and the objects representing them, which have similar attributes can be grouped together, for example into object classes. Thus in a network management representation of a network resource, the network resource is an object which is characterized by its object class and object instance, and can possess multiple attribute types and associated values. Managed object classes and their properties are used to provide information which is to be exchanged across interfaces (as defined in recommendation M.3010, telecommunications network management (TMN) architecture, also of the ITU-T). Object classes however, may apply to various management areas, for example fault management and configuration management.
Conventionally, however, the concept of describing network resources has been subject to certain limitations, in particular, no attempt has been made to address issues in which the internal characteristics of the network resource, in particular, its physical connectivity restraints require modelling. For example, ITU recommendation G.774 assumes potentially infinite flexibility of configuration of a described physical resource, whereas in practice there are practical limitations on the possible configurations of a resource. For example, physical resources may be subject to hard wired restrictions as a result of restrictions in an application specific integrated circuit (ASIC). Thus, irrespective of the way in which the physical resource is modelled in an information base, physical limitations on connectivity of the physical resource may exist.
Consider a physical resource having four ports numbered 1 to 4. Ports 1 and 2 may be capable of connecting with each other. Moreover, port 1 and port 2 may be able to connect also to port 4. However, ports 1 and 2 may be incapable of connecting to port 3 due to a hard wired restriction on connectivity in the resource, and port 4 may not be able to connect to any ports, only to receive traffic from ports 1 and 2.
Recommendation G.774 does not provide a way of expressing such connectivity restriction, but assumes any port of the physical resource can be connected to any other port of the physical resource. Recommendation G.774 does not provide for description of such inherent capability restrictions in a physical resource.
U.S. Pat. No. 6,223,219, the full text of which is incorporated herein by reference, provides a trail management system which enables trails (effectively end-to-end network connections) to be modelled and stored in terms of a state model describing their operational state etc., in a database which can be accessed by a network operator. The network management system described in U.S. Pat. No. 6,223,219 enables trails to be identified within a network and enabled a network operator to check that the actual physical trails were consistent with the stored trail data.
As network complexity increases, it is extremely advantageous if a network operator is able to offer a variety of different services relating to connection cost, Quality of Service, protection etc.
Currently, when a network operator builds a trail, it is possible that certain features which would add value to the trail, such as additional protection options, are not apparent. It is extremely advantageous if during the construction of a trail, a network operator (regardless of whether this is a interactive or an automatic operation) is able to recognise that particular elements in the trail either have or could have certain features.